Boys are trying to mount one another - is this just a power struggle?

[Celestrina]

I'm not sure if they are playing or fighting.  They are two brothers who just came home today.  Should I consider having them neutered?  One thing I like about rats is that it is obvious that they are both boys and that there won't be more cagemates soon.

[Dearpie]

They're just trying to establish dominance.  Nothing to worry about. 

[Celestrina]

Thanks, that's a relief.  perhaps I posted too soon; now they are curled up together in the corner.